Designs have been proposed for containers used with flowable substances wherein a closure is provided for being attached to the container mouth and wherein the closure includes a toggle-action actuator, flip-up spout, or nozzle assembly for dispensing the container contents. See, for example, U.S. Pat. Nos. 5,058,775, 4,962,869, 4,776,501, 4,645,086 and 3,516,581.
The toggle-action closures, such as those disclosed in the above-referenced U.S. Pat. Nos. 5,058,775, 4,962,869, and 4,776,501, require that the operator push down on a top, rear portion of the closure in order to pivot the actuator of the closure to the dispensing orientation.
When the actuator is pivoted to the dispensing position, a discharge passage in the actuator is in communication with the container contents, and the container contents can flow out through the actuator. Typically, such toggle-action closures are provided on squeezable containers fabricated from a thermoplastic material providing a inwardly deformable, resilient wall structure. When the container wall structure is squeezed, the contents within the container are forced upwardly and out through the open dispensing closure.
During shipping and handling, a toggle-action closure may be accidentally bumped or impacted in a way that causes the closure to pivot to the dispensing orientation. It is then possible for the contents to be discharged. If the container is lying on its side, the contents can leak out of the accidentally opened closure. If the container is in a carton, the carton may be subjected to rough handling causing the wall of the container to be temporarily squeezed inwardly and causing an unwanted discharge of a portion of the container contents through the open closure.
In order to prevent or substantially minimize the potential for leakage or spillage of container contents during shipping and handling of containers provided with toggle-action closures, the closure of the type disclosed in the above-referenced U.S. Pat. No. 4,962,869 was developed. This closure has effectively solved a long-felt need to prevent inadvertent discharge through toggle-action closures during shipping and handling.
The closure disclosed in the U.S. Pat. No. 4,962,869 provides a unique structure which prevents or greatly inhibits the opening of the toggle-action actuator during shipping and handling. In particular, the closure body is provided with an upstanding abutment or resistance post under a rear portion of the toggle-action actuator. The actuator includes a shearing wall for confronting the abutment post when the actuator is initially closed in the non-dispensing position. When a moderate force is applied to the rear of the actuator, the actuator will not tilt upwardly to the open position because the shearing wall engages the abutment.
The abutment is designed to withstand the forces typically encountered during shipping and handling. However, the abutment is designed to be sheared off when the actuator is subjected to at least a predetermined force greater than the forces typically encountered during shipping and handling. When the consumer uses the closure for the first time, the consumer must apply, to the rear of the actuator, a force at least equal to the predetermined force so as to cause the shearing wall to shear off the abutment. Thereafter, the consumer can subsequently open the actuator by applying a much lower force.
The above-discussed design disclosed in the U.S. Pat. No. 4,962,869 functions very well and satisfies the objectives of preventing or inhibiting leakage during shipping and handling. However, the precise magnitude of the force required to shear off the abutment is not easily determinable, and the required shear force may vary somewhat from closure to closure. It would be desirable to provide an improved design in which the required shear force could be more predictable and controllable.
It would be also desirable to provide an improved dispensing closure with an actuation-prevention abutment that could be molded from thermoplastic material in a mold assembly that is less fragile and that is subject to less manufacturing variation.
The present invention provides an improved closure which can accommodate designs having the above-discussed benefits and features.